Optimal hold functions for MDCS sampled-data problems

In this paper the H/sup 2/ and H/sup /spl infin// sampled-data problems with mixed discrete/continuous specifications (MDCS) are considered. The hold function is not fixed a priory but rather is the design parameter. The (sub-)optimal controller obtained is of the form of a serial interconnection of a (sub-)optimal digital controller and a (sub-)optimal hold function.